Powershell scripts to encrypt/descrypt a string using a public and a private key (SHA256 and higher)

MAIN PROJECT I would like a develioper who is able to provide me with: 1. A Powershell script which can encrypt a string (plain text) and produce a public and a private key and a Initialization vector (IV). It is prefered that I can determine one of the keys and maybe the [login to view URL] encryption algorythm must be at least SHA256. 2. A Powershell script which can decrypt a string, using the public and private keys as well as the IV. OPTIONAL PROJECT I am looking for a way to produce FIXED LENGHT keys (and maybe IV) no matter how long the plain text is. Example 1 (numbers are not real and are justfor de3monstration purposes): Suppose that we want to encrypt a sentence containing 10 words. The length of the public key will be 64 characters. The length of the private key key will be 150 characters. Example 2: Now we want to encrypt a sentence containing 500 words: Again, he length of the public key will be 64 characters. The length of the private key key will be 150 characters. Is this possible in cryptography? For the optional project, security is not my concern. My concern is the FIXED LENGTHS only! ABOUT YOUR BIDS Please don't waste my time with negotiations. Leave separate FINAL bids for each project PAYMENT I will not release any milestone until I will test the developer's work and make sure is working as expected (at least on my PC)! For this reason, the developer must submit his/her work (prior to payment) in order for me to test it. Since everything is fine and any bugs will be corrected by the developer, I will release the milestone! Thank you